Caster



Sem. 16 1924. 1,508,880

W. F. HEROLD CASTER Filed April 28 1924 f ly Patented Sept. 16, i924.

UNITED STATES 1,888,888 PATENT carica` WALTER r. HERoLn, or NEWARK, NEWJERSEY, Assreivon; 'ro THE BAssrcK coivr-l PANY, OF BRIDGEPORT,CONNECTICUT, A CORPORATION yOIE CONNECTICUT.

CASTER.

Application filed April 28, 1924. Seria1 No. 709,343.

T0 aZZ whom t may concern.'

Be it known that I, INALTER F. HEROLD, a citizen of the United States,and resident of Newark, in the county of Essex and State of New Jersey,have invented certain new and useful Improvements in Casters, of whichthe following is a specification.

The invention relates to improvements in casters, and particularly toimprovements in the caster horn. An object ofthe invention is theprovision of a horn so shaped and reinforced as to resist the stressesto which the same is subjected in use more effectively than other hornsof similar thickness of metal with which I am familiar.

It is common practice to press up the metal of the transverse topport-ion of the horn to form a circular reinforcement through the centerof which extends the opening in which the lower end of the caster pintleis riveted. This circular domed or arched reinforcement forms the seatupon which rests a shoulder on the pintle or washer surrounding thepintle through which the weight carried by the .caster is transmitted,thro-ugh the horn, to the caster wheel or other rolling member.

v The circular dome was, of course, provided in an effort tol reinforcethe top portion of the horn against bending or deformation of the samebecause of the weight transmitted to the center thereof, as well as towithstand the stresses due to forces tending to tilt the pintle. Otherattempts to reinforce the top portion of the horn have aimed to stiffenthe front or rear edges, as by turning downwardly the front or rearedges,ior both, of the horn top portion or yoke.

I have determined that none of these devices served to resist thestresses imposed upon the horn yoke in the most effective manner, andhave found that thedesired object may be accomplished by a simplemodification lof the previously used central doming of the yoke. Suchdoming is advantageous in stiffening the central portion ofthe yoke.Experience shows however that yokes having a central circular dome areliable to downward deformation along the front edges of the yoke, thatis, .the edge of the yoke located between the planes of the caster wheeland pintle axes. I have found that this is due to ,forces actingtangentially to the circular boss or dome of the yoke. If, however, thefront edge only of the yoke is stiffened, the yoke is liable todeformation between the pintle opening and the stiffened edge. l

.n I overcome these difficulties most effectively by making use of thedome o-r boss about the pintle, but extending the same forwardly so asto interpose arched metal in the line of the tangential forces referredto. This may be accomplished, for eX- ample, by extending the circularboss forwardly, to make a Dshape, with the base of the D parallel andadjacent to the front edge of the yoke.

The invention consists in the improved caster hornk referred .to and inthe various combinations of yparts and details of construction thereof,all as will be more fully set forth in thefollowing specification inconnection with the preferred embodiment thereof, and be particularlypointed out in the appended claims.

In order that the invention maybe more clearly understood attention ishereby directed to the accompanying drawings formingvpart ofthisapplication and illustrating one embodiment of the invention. In thedrawings- Fig. l represents aside elevation of a caster horn, the armsof which carry a caster wheel and the yoke or top portion of which has acaster pintle secured thereto;

Fig. 2 is an enlarged partial longitudinal section taken through thecaster horn with the pintle shown in side elevation, thissection beingtaken on line 2 2 of Fig..3

Fig. 3 is a top plan view of the caster horn and pintle on a furtherenlarged scale, this view also,I showing the manner in which failuremight occur in a horn having a circular dome or boss thereon, and

Fig. 4: is a transverse vertical section taken on line i-4l of Fig. 2.

Referring to the drawings, the caster Ahornv i comprises the arms l, l,which extend downwardly from the yoke or transverse top portion 2. Thecaster wheel 3 is rotatably supported on `the usual axle L carried bythe arms l. The pintle 5 is secured on the yoke or top horn portion2,1in usual fashion as by having a portion 6 thereof extend through thecentrally located pintle opening in the yoke of the horn, the bottom endof the pintle beingA upset, as shown at 8, beneath the yokeV of thehorn.

llO

The yoke or transverse top portion of the horn is provided with anupwardly extending reinforcement 9, which, as shown, is approximatelyD-shaped, the base of the D being formed by the front edge 10 of thereinforcement, adjacent to the front edge 11 of the yoke, that is tosay, the transverse edge of the yoke nearest to the axis of the casterwheel. The reinforcement is preferably domed or arched upwardly to acompara-tively small height, by pressing the metal of the yoke upwardlyin the form indicated, the horn being formed of sheet metal, as isusual. lith this construction the dome or reinforcement 9 has asemi-circular rear portion 12 and a forwardly extending portion havingsidel edges 13, 13, which connect the semi-circular rear portion 12 withthe front edge 10 of the D reinforcement. rThe horn is arched at thejunctions of the yoke 2r and arms 1, as is usual, the arched junctionsbeing indicated at 14; in Fig. 4l. The side edges 13 of the D-shapedreinforcement preferably extend forwardly over the arches 111 of thehorn, these side edges 13 being more or less parallel to the planes inwhich the arms 1 of the horn are located.

In the prior construction referred to, in which a circular dome or bosswas provided on the yoke, the forwardly extending sides 13 joined by thefront edge 10 of the reinforcement are, of course, not present, suchcircular boss being made up of the semi-circular portion 12 of thepresent boss and the front semi-circular portion 15 indicated in dashand dotted lines on Fig. 3. With any caster of the character referred tothe weight borne by the furniture leg is transmitted from the pintle tothe yoke, and thence lto the arms of the horn, and thence to the casterWheel. The pintle may be provided with an annular shoulder 16 whichrests on the' boss or dome of the yoke and transmits the Weight of theleg to the yoke. j

-With the prior circular dome on the yoke the crushing force thustransmitted to the yoke acted along the lines of least resistance in theyoke to cause bending thereof, when the applied force was greater thanthe capacity of the yoke to withstand without deformaion. I havedetermined experimentally that this crushing force was exerted along thetangential lines indicated in dot and dash in Fig. 3 at 17, 17, theselines being tangential to the circular boss or dome and converging so astol meet at a point 18 forwardly of the front edge of the yoke, over thecaster wheel. These lines of stress are tangential to the boss orreinforcement because of the fact that the arched metal of thereinforcement stiffens this part of the yoke, and they' are inwardlydirected at angles as indicated, because of the fact that f the archedjunctions 14 between the yoke and arms of the horn stiffen the horn atsuch junctions and cause the yoke to deform along lines which are spacedinwardly from these arched portions 111. rIhe lines of stress referredto extend forwardly, that is towards the caster wheel, because of thefact that the force must be transmitted forwardly from the pintle to theaxis of the wheel, and also because of the fact that the axis of thewheel being in a different vertical plane from that of the axis of thepintle, the downward force at the axis of the pintle and thecorresponding upward reaction at the axis ot the wheel cause a tiltingmovement which tends to tilt the pintle forwardly. This latter action isaccentuated when the wheel strikes against an obstruction such as theedge of a carpet, in moving the furniture. rIhe most violent strain towhich the caster horn may be put, however, is caused by dropping thefurniture, when it has been lifted, in which case the force tending todeform the front edge of the yoke of the horn may be very severe.

-Vith the improved construction described herein the action referred tois to a very great extent prevented by the interposition of reinforcingmetal along the lines 17, 17, this reinforcing metal being provided bythe corner portions 19, 19, of the D-reinforcement (Fig. 3), thesecorner portions comprising domed or arched portions of the upwardlypressed dome 9. Accordingly, the front edge of the yoke cannot be bentdown wardly with my improved construction to any perceptible extent by aforce which would bend downwardly on a considerable curve, the forwardedge of the yoke in the prior construction having the circular domedboss.

`Tith the improved construction any forwardly directed lines of forcetangential to the portion 9 of the boss would extend alongside the edges13 of the boss which extend over or lead into the arched portions 111 ofthe horn. These arches 111 of the horn constitute, of course, stiffeningportions of the construction, and the domed reinforcement surroundingthe pintle opening in the yoke is also a stilfening portion of theconstruction. It is not necessary, according to the data obtained by me,to stiffen the rear edge of the yoke in the same manner, the circularportion 9 of the boss surrounding thel pintle opening at the rear beingsuflicient for the purpose.

What I claim is:

1. In a caster, a horn having a transverse top portion and forwardly anddownwardly extending arms, said top portion having an upwardly-extendingreinforcement vof substantially D shape, with the base thereof adjacentand parallel to the front edge of said top portion, said reinforcementhaving a pintle opening therethrough.

' ing extending therethrough, said reinforcement extending around thepintle opening at the rear, having side edges extending forwardly insubstantially straight lines -above the arched portions of the top, anda front edge between said side edges, adj acent to the front edge ofsaid top portion.

3. In a caster, a horn of pressed metal having a transverse top portionand forwardly and downwardly extending arms, the horn being arched atthe junctions of the top portion and arms, andthe top portion having aportion thereof pressed upwardly to form a domed reinforcement with apintle opening extending therethrough, said reinforcement extendingabout the pintle opening at the rear, having side edges' extendingforwardly substantially beyond the pintle opening in substantiallystraight lines, above the arched portions of the top, and a front edgebetween said side edges. l. In a caster, a horn having a transverse topportion and forwardly and downwardly extending arms, the horn beingarched at the junctions of the top portion and arms,

and the top portion having an upwardly extending reinforcement with apintle opening extending therethrough, said reinforcement extendingaround the pintle opening at the rear, and having portions at the sidesl of the pintle opening extending forwardly beyond the same, positionedin the path of all forwardly extending bending stresses at the sides ofsaid rearward portion other than those directed solely into the archedjunctions between the horn top and arms.

5. In a caster, a horn of pressed metal having a transverse top portionand forwardly and downwardly extending arms, the horn being arched atthe junctions of the top portion and arms, and the top portion having aportion thereof pressed upwardly to form domed .reinforcement with apintle opening extending therethrough, said reinforcement extendingabout .the pintle opening at the rear, and having side edge portionsextending forwardly at the sides of the pintle opening, adjacent to thearched edge portions of said horn top and substantially paralleltherewith, said side edge portions of said reinforcement being connectedby a transverse front portion in front of the pintle opening.

In testimony whereof I have signed my name to this specification.

WALTER F. HEROLD.

